Dry mouth of postoperative makes the patient feel thirst, and the pain of the lips is cracked. It will also make the sputum thick and sticky, making it difficult for the patient to cough by himself. Especially the elderly may have sputum accumulation and pneumonia. Dry mouth can easily change the pH value in the mouth, destroy the environment in the mouth, and increase the chance of oral mucosal lesions, ulcers and infections. The physical discomfort can lead to psychological effects such as anxiety, irritability, and irritability. The incidence of dry mouth was 88%, 6-8 hours after abdominal surgery. Although the incidence is high, compared with other complications after surgery (such as: pain, bleeding, etc.), dry mouth after surgery is less important, and is underestimated, unmeasured, unrecorded and untreated. Initiating the motivation of this study, it is hoped that through research to understand the relevant factors causing dry mouth after surgery, and using transcutaneous electrical nerve stimulation (TENS) to improve the symptoms of dry mouth after surgery. The first phase is to describe the relevant studies with the aim of understanding the relevant factors that contribute to dry mouth after surgery. This study will understand and pay attention to the post-operative dry mouth. It is hoped that through this study, the problem of dry mouth after surgery will be improved, and the comfort of the recovery period after surgery will be improved, so that patients can get better care and promote the quality of care.

Introduction A postoperative thirst is one of the major complaints in the recovery room. The purpose of this experimental study was to compare the efficiency of reducing postoperative thirst by transcutaneous electrical nerve stimulation (TENS) and routine care.

Methods Surgical patients under general anesthesia were recruited from a medical center. Each patient was randomly assigned to the experimental group (TENS) or control group (routine care). Experimental group had 53 patients and control group had 52 patients fitted in the inclusion and exclusion criteria and completed data collection. The intensity of thirst was measured pretreatment, immediately after treatment and 30 minutes after treatment. All data were managed by SPSS for Windows (version 21.0). Descriptive and inferential statistics (Chi-square test, t-test, generalized estimating equation regression analysis) were performed to identify the relationships that were proposed.

Inclusion Criteria:

• Anesthesiology (ASA) physical status I-ΙII, elective abdominal surgery, >20 years old

Exclusion Criteria:

• pregnancy, epilepsy, unconscious